146 
OF THE MOSSES AND THEIR ALLIES. 
the fruit is situated at the summit of a stem, and the 
Pleurocarpi, which bear the fruit on the sides. In one 
word, in the first, the theca or capsule is terminal; in the 
second it is lateral. This difference of structure necessitates 
a difference of treatment in preparation. Bunches of the 
lateral fruited species may be separated by the hand without 
taking the trouble to isolate individual plants : it is better, 
in fact, to leave them massed together, as showing their 
character of growth more accurately. With the terminal 
fruited species, on the contrary, the natural habit of the 
plants is seen better if they are separated, though they 
need not be entirely so. For this purpose, two or three 
clean cuts may be made with a knife through the tuft, 
from above downwards, thereby making thin sections held 
together slightly at the bottom, either by the adherent 
earth, or by their own interwoven roots. 
Some of the very delicate kinds, such as Brachyodus or 
Seligeria, and many of the Jungermannise should be collected 
together with the bark or stone to which they have at- 
tached themselves. 
The Hepaticse need great care in their preparation ; not 
the least difficulty is the getting rid of the soil from their 
roots without injuring the leaves or breaking the stem. 
The best method of accomplishing this is to lay the plants, 
just as they are brought home, in a cup of clean water, 
then, by a gentle movement of the fluid backwards and 
forwards, the earth will gradually separate itself and settle 
at the bottom. The water should be constantly renewed, 
until no signs of discoloration appear. Next let the plant 
be carefully lifted out of the cup and laid on soft paper to 
allow of the water draining off. Here, again, great care is 
needed, because some of the important parts are easily 
broken off and lost from their extreme minuteness, if any 
roughness or over-haste is used; such are the so-called 
gemmae, the calyx or vaginule, and the antheridia, on 
their short pellucid footstalks. 
An ordinary lens is sufficient for the examination of the 
stems and branchlets of the Mosses ; but the construction of 
